Slide-rule.



C. F. DIECKMANN.

' SLIDE RULE.

APPLICATION man ocT.19, |914.

PatentedSept. 28, 1915.

kil i i UNITED` STATES PATENT OFFICE.

-GARL F. DIECKMANN, OF CHICAGO, ILLINOIS, ASSIGNOR T0 EUGENE DIETZGENCOM- SLIDE-RULE.

Specification of Letters Patent.

Patented Sept. 28, 1915.

Application led October 19, 1914. Serial No. 867,271.

T 0v all whom it may concern Be it known that I, CARL F. DIECKMANN, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented a certain new and usefulImprovement in Slide-Rules, of which the following is a specication.

My invention relates to slide rules, and the general object of theinvention is to provide a rule so constructed that a desirable amount offriction will always be created whenever the. slide is moved, therebypreventing the Slide from being moved too easily on the one hand and onthe other hand permitting the slide to be moved when a slight but firmlongitudinal pressure is exerted upon it.

Itis well known to makers and users of slide rules that the action ofthe slide is frequently influenced by atmospheric conditions, the slidehaving a tendency to stick or requiring excessive pressure if theweather is too damp, and moving too freely if the rule is left where theair is dry and comparatively warm. Rules of this character are alsosubject to warping, in which case the device may be rendered practicallyuseless.

y The object of my invention is to produce a rule which will not beaffected by temperature conditions and which will still be operativeeven though the parts should beplained.

I accomplish my objects by the mechanism illustrated in the accompanyingdrawings in which Figure l is a view showing the top of the'rule andslide. Fig. 2 isa view of the bottom of the slide with a portion of thefacing removed to reveal the spring mechanisrn. Fig. 3 is a perspectiveview of the spring in its preferred form. Figs. 4 and Vrule t beingseparate. ternal longitudinal grooves 5 which receive 5 are sectionalviews on the lines 4 4 and 3;5 respectively. F ig. 6 is a longitudinalsection on the line 6 6 of Fig. 2 showing the spring in position.

Similar numerals refer to similar parts throughout the several views.

vThe slide l is of ordinary form and of ordinary marking, a suitableform of marking being suggested in Fig. 1. Under ordinary circumstancesthe markings-that is, the scalesware imprinted yupon facing strips la ofCelluloid or other suitable substance. On each side of the slide is arule,the rule 2 being integral with the base 3 and the Said rules haveinthe longitudinal tongues G in the ordinary manner.

My invention consists more particularly in the manner of connecting theseparate rule a to the base 3. At suitable intervals along the base, inthe bottom thereof, I form slots 8, the number of these slots in thepresent instance being three. Each of these slots is for receiving thevibrating end of the spring l0 shown separately in Fig.

o. At the stationary end the spring has an eye 1l, and in manufacturingthese devices I remove, under ordinary circumstances, enough of the woodof the base to let the stationary portion of the spring into the basewithout splitting the latter. In other words, in constructing the parts,approxinately one-half of the spring is let into the base from thebottom snugly enough to prevent any movement of the stationary portionof the spring, while the remaining portion of the spring, which forconvenience I term the vibrating portion, lies within the slot S. Byreason of the width of the slot the vibrating portion of the spring isfree to swing from side to side for a considerable distance in eitherdirection before coming into contact with the wall of the slot. Slot 8preferably extends through from top to bottom of the base substantiallyin line with and beneath the center of the movable rule 4;; and bypreference the spring is of a height equal to the height of the base ofthe rule at this point. Two laterally projecting ears 12, l2, are formedat the bottom of the spring, these ears underlying the bottoni of thebase but being countersunk thereinto far enough to leave a smoothsurface at the bottom of the base. Another' ear 13, which is preferablyof larger size, also underlies the base. A counter-sink or recess 14 isformed in the bottom or base for permitting` free lateral movement ofsaid ear and the vibrating portion of the spring. The spring is securelyfastened to the movable rule 4 by a tongue 15, which projects up intothe body of the movable rule, and has two ears 16, which overlie the topof the movable rule and prevent the latter from rising. The ears 1Gextend in opposite directions in the preferred construction, and therule should be countersunk sufficiently to let the top of the ears 16come flush with the top of the rule. As a result of this constructionthe rule is free to adjust itself transversely to the left of the devicebut is firmly held in every other respect by the spring. The eye 11prevents the spring from shifting longitudinally within the base, andthe ears 12 and 13 prevent the spring from rising in the base, while theears 16 prevent the rule from rising from the base. Thus all relativemovement between the rule 4 and base 1 is prevented except thetransverse movement of the rule 4.

. In finishing the rule it is desirable to apply a surface strip 4 tothe top of the rule 4, and a surface strip 3a to the top of the rule 3.Said strips are preferably of celluloidor other' suitable substance andbear the scale markings which coperate with the yscale markings on thesurface strips 1a on the slide. The surface strip 3b is similar andni'ay have any suitable markings thereon such as data commonly used byengineers. The strips 3b and 4a serve the additional purpose of coveringup the slots and ears of the spring with the result that in the finishedarticle the spring and its various projections are all invisible.

In operation, the springs force the movable rule 4 firmly but gentlyagainst the edge of the slide 1 thus creating a reasonable amount offriction and holding the slide at any position to which it may bo set,without in any manner binding it. The width of the slots 8 permitsconsiderable transverse play and hence within any reasonable limit thesprings will permit the movable rule 4 to accommodate themselves to anychanges in the parts due to variations of atmospheric conditions.Furthermore, the rule will remain operative even though the slide orother parts of the rule should become warped within any reasonablelimits. The springs permit transverse play but on account of the variousears with which it is provided it prevents the movable rule 4 from beinglifted from the base, and on account of its peculiarrconformationeffectually prevents the movable rule from moving longitudinally uponthe base. As the construction affords resilience through a comparativelywide range of movement, adjusting means are entirely dispensed with andthe spring mechanism may be and is entirely inclosed within the device.

Having thus described my invention, what I clainr as new and desire tosecure by Letters Patent, is

1. In. a slide rule, the combination of a slide, a base having a flatupper surface parallel to the plane of the rule, a guide for said slideseated on the fiat upper surface of the base, and a leaf spring arrangedon edge and extending, in the main, longitudinally of the rule, saidspring being fastened at one end to the base and at the other end to theguide whereby the guide is held in contact with the upper surface of thebase but permitted to slide thereon for frietionally holding the slide.

2. In a'slide rule, the combination of a slide, a base having a flatupper surface parallel to the plane of the rule, a guide for said slideseated on the fiat upper surface of the base, and a leaf spring arrangedon edge and extending in the general direction of the length of therule, one end of the spring being embedded in the base and the other endembedded in the guide, and one of the parts being slotted for permittinglateral movement of the spring, to permit the guide toy yield and slidealong the surface of the base when pressed by the slide.

, 3. In a slide rule, the combination of a slide, a base, a rule forguiding said slide, and a flat spring for securing said rule to saidbase and permitting transverse movement of said rule, said spring beingarranged on edge, and the major portion thereof terminating beneath thebottom of said rule, said spring rising at one point up into said ruleand being there securely fastened, the base being slotted to permittransverse movement of the spring where it rises into the rule, and theother end of the spring being fastened to the base, substantially asdescribed.

4. In a slide rule, the combination of a slide, a base having a fiatupper surface, a guide seating upon said surface, a leaf spring embeddedin the base and extending longitudinally thereof, the base being slottedadjacent to the spring for a portion of the length thereof to permit thespring to move laterally, the laterally moving end of the springextending up into and being fastened to the guide, whereby the guide isheld in frictional contact with the slide and is prevented from leavingits seat upon the flat upper surface of the base.

5. In a slide rule, in combination, a base, a slide, a separate rulemounted upon said base for guiding said slide, said base having alongitudinal slot lying beneath said rule, a leaf spring arranged onedge, one

portion of said spring lying within said slot and projecting upward atits end into and through the rule and being fastened to said rule, theremaining portion of said spring being securely fastened to the base andan ear projecting transversely from said spring at the bottoni thereofat the slotted portion of the base and underlying a portion of the base,said ear being slidable upon the under surface of the base forpreventing the rise 10 of said spring.

In witness whereof, I have hereunto subscribed Iny name 1n the presenceof two Wit- Copies of this patent may be obtained for ive cents each, byaddressing the Commissioner of Patents, Washington, I). C.

